Much progress has been made toward identification and development of biocides for controlling various molds, plant diseases and the like. However, most commercial biocides or pesticides in use are compounds which are classified as carcinogens or are toxic to wildlife and other non-target species. For example, methyl bromide is widely used as a soil fumigant and in the post-harvest treatment of microbial infections. Human toxicity and deleterious environmental effects will ultimately result in discontinued use of methyl bromide and various other synthetic biocides/pesticides. As a result, recent efforts have been directed to the identification and development of natural or biomimetic compositions demonstrating comparable antimicrobial or pesticidal effect.
One such approach relates to endophytes and associated volatile by-products. Endophytes are defined in the art as microorganisms residing in the interstitial spaces of living plant tissue, but are generally not considered to be parasitic. In particular, endophytes found in conjunction with rain forest plants have generated considerable interest for reasons relating to the antibiotic character of their volatile by-products. Several members of the Muscodor genus (i.e., M. albus, M. roseus and M. vitigenus) have been shown to produce volatile by-products exhibiting antibiotic or insecticidal character. However, the respective by-product of each species includes various naphthalene and/or azulene derivatives. Such compounds, together with other by-product components, can be toxic or otherwise unhealthy, and the corresponding mixtures are considered unacceptable for various end use applications. Accordingly, there remains an on-going search in the art to identify natural compositions and to develop biomimetic compositions absent from such compounds, that are safe for human use and demonstrate effective antimicrobial properties.